Various types of floor cleaning implements are known in the art. Vacuum cleaners typically come in either the upright, canister, or stick type configurations. One feature of a typical upright vacuum cleaner is a base unit that carries an upper body containing a dirt and/or dust collection container. The upper body is typically tiltable relative to the base unit. The tiltable upper body has two positions: a parked position and an operating position. In the parked position, the upper body can be held in a nearly upright position when the base unit is located on a horizontal floor. In this position, the upper body stands unsupported. During operation—that is, vacuuming—the upper body is tilted back from the parked position through a certain range of operating angles. The actual operating tilt angle or angle range may depend on such variables as the expected height of the operator, the particular purpose of use, or the structural design of the tilting mechanism. The operating position typically comprises free movement through the operating angle, but it may be possible to lock or resiliently hold the upper body in certain discrete angular positions that are tilted back from the parked position. A lock mechanism typically is provided to resiliently or rigidly hold the upper body in the parked position, and this lock may be released by a mechanism of some form that is typically actuated by the operator.
A typical vacuum cleaner also includes a handle provided on the upper body for maneuvering the vacuum cleaner when it is in the operating position. The handle may be a separate part or integrally formed with the upper body. A typical vacuum also includes a motor-fan unit, located either in the base unit or upper body, or in a remove vacuum in the case of central vacuum cleaners, to generate airflow through the vacuum cleaner to allow it to function as a vacuum. An airflow path, typically formed by hoses and/or ducting, is established between the base unit and upper body.
These conventional upright vacuum cleaners have a disadvantage in that they can be difficult to maneuver about an area in which they are used. They can be pushed and pulled easily enough, but pointing the cleaner in a new direction is more difficult. The cleaner can be pointed in a new direction by applying a sideways directed force to the handle, either from standstill or while moving the cleaner forwards or backwards. This causes the cleaner head to be dragged across the floor surface so that it points in a new direction. The only articulation between the base unit and the upper body is about a single pivot axis oriented parallel to the floor, and perpendicular to the fore-aft axis of movement. In most upright vacuum cleaners, a one or more sets of supporting wheels are mounted on the base unit to aid in moving the vacuum cleaner across the surface to be cleaned.
Attempts have been made to increase the maneuverability of upright vacuum cleaners or canister and central vacuum cleaner wand units. Some examples are shown in U.S. Pat. Nos. 5,323,510 and 5,584,095, the disclosures of which are incorporated herein by reference. In both of these patents, the vacuum cleaners have a base that includes a motor housing and a pair of wheels. A connection between the base and the main body incorporates joints that permit articulation about multiple axes. One part of the joint provides typical backwards tilting as described above (i.e., rotational movement of the main body with respect to the base about a first axis that is parallel with both the horizontal plane (i.e., the floor) and the rotational axis of the wheels). Another part of the joint provides swiveling movement about a second axis oriented perpendicular to the rotational axis of the wheels and inclined with respect to the horizontal plane. U.S. Patent Application Publication Number 2009/0056065, which is also incorporated herein by reference, shows a similar arrangement.
U.S. Pat. No. 7,610,653, which is incorporated herein by reference, shows an upright vacuum cleaner with a main body having a user-operable handle, and a support assembly that is mounted to the main body and arranged to roll with respect to the main body for allowing the appliance to be rolled along a surface by means of the handle. The support assembly is rounded to permit the main body to tilt laterally, and the provision of this rolling support assembly aids maneuverability of the cleaner.
Other prior art devices include support wheels that are mounted on casters that permit the wheels to swivel about a vertical axis. Such devices provide maneuverability because they allow the user to move the base laterally or rotate is about a vertical axis without lifting it from the floor, but these devices can be difficult to push in a straight line when desired and the use of casters may require some lateral movement each time the user transitions from forward to backwards movement.
Other prior vacuum cleaners use a universal-type joint that provides two rotation axes between the base and the upper body. An example of such a device is shown in U.S. Patent Application Publication Number 2008/0040883, which is incorporated herein by reference. In these devices, a first pivot provides typical backwards tilting, and another pivot provides a similar tilting movement in the lateral direction. The lateral tilt pivot is generally perpendicular to the long axis of the upper body, and allows the upper body to pivot left and right relative to the base.
The present invention provides unique alternatives to known cleaning devices, and various new and useful features that may be used with otherwise conventional cleaning devices.